First, Facebook was the "it" girl of social media. Then, Twitter came into the spotlight and now Instagram has officially topped Twitter in popularity. The List's Ariel Wesler talks to social media expert, Chris Kline (ABC15) about the major shift and what to expect in 2015. See the full story now, on The List!

Some school officials try to prevent students from tweeting in class. But others are embracing social media as a learning tool, saying sites like Twitter can expand discussions beyond a classroom's four walls.